1. Field of the Invention
This invention relates to disk drive suspensions, and more particularly to improvements in the manufacture of disk drive suspensions having flexible conductors attached to the load beam and flexure portions of the suspension. In a specific aspect, the invention provides for the adhesive attachment mounting of flexible conductors comprising a laminate of two or more conductors and flexible plastic film to a suspension load beam and/or flexure from the back, or non-slider, side of the load beam and flexure with fewer process step, less handling of the small parts, and reduced opportunity for manufacturing error.
2. Related Art
Flexible conductors are used in disk drive suspensions in lieu of wires to conduct electrical signals between the read/write head and the device electronics with the flexible conductors being adhesively bonded to the suspension load beam. See U.S. Pat. No. 5,491,597, for example. The attachment or mounting of the flexible conductors can be problematical with manufacturing difficulties being of paramount concern. Adhesives must be placed in precise locations and in concert and not conflict with other manufacturing steps. Typically, as in the above-referenced patent, the conductor is on the slider side of the suspension and must be bonded by application of the adhesive between the conductor and the suspension load beam, necessitating several steps involving manipulation of the conductor and load beam to get suitable access to the bonding areas, effective alignment of parts and curing of the adhesive. This has required approaching the assembly first from one side then the other, with consequent extra process steps such as double fixturing, both sides cure, and their increased risk of damage or error.
It is an object of the present invention to provide an improved method of mounting a flexible conductor to a suspension load beam, suitably from a single side of the load beam so as to reduce handling and opportunity for error while maintaining proficiency in attachment. It is a further object to provide mounting locations for the adhesive placed so as to be accessible from the back side, or non-slider side, through which adhesive is flowed and cured all from the same side. It is a further object to provide an assembly for bonding in which the aligned flexible conductor and load beam or flexure substrate has a port into which flowable adhesive is forced in sufficient quantities to overflow the port perimeter above and below the port forming, with cure a crown providing mechanical as well as adhesive locking of the aligned parts together.
These and other objects are realized in accordance with the invention in the single-side method of mounting a flexible conductor to a suspension comprising a flexure and a load beam, that includes forming in the suspension a flowable adhesive-passing channel at a locus of flexible conductor attachment to the suspension, the channel having an inlet and an outlet, engaging the flexible conductor and suspension in their desired alignment with the flexible conductor adjacent the channel outlet, forcing a flowable adhesive into the channel inlet, through the channel and between the aligned suspension and flexible conductor in a manner forming a crown of the adhesive over and around the channel inlet, hardening the adhesive in bonding relation with the flexible conductor and the suspension, the adhesive crown mechanically locking the suspension and flexible conductor in their the desired alignment, and the resulting product.
In this and like embodiments, typically, the method further includes forming a series of laterally and longitudinally distributed channels for registration with a plurality of attachment loci for the flexible conductor and the suspension, and where there is a flexure as well as a load beam in the suspension, further forming at least one the channel in the load beam, and forming at least two the channels in the flexure, e.g. on flexure left and right tabs projecting beyond the load beam, and there is included also forming one of the two flexure channels in each of the flexure tabs, the flexible conductor being fixed to the tabs and fixed to the load beam with the adhesive.
In a further embodiment, the invention provides the single-side method of mounting a flexible conductor to a suspension comprising a flexure and a load beam, including forming in the suspension a flowable adhesive-passing channel at a locus of flexible conductor attachment to the suspension, the channel having an inlet and an outlet, engaging the flexible conductor and suspension in their desired alignment with the flexible conductor adjacent the channel outlet, forcing a radiation curable, flowable adhesive into the channel inlet, through the channel and between the aligned suspension and flexible conductor in a manner forming a crown of the adhesive over and around the channel inlet, curing the adhesive by radiation exposure at the channel inlet, the adhesive curing in bonding relation with the flexible conductor and the suspension, the adhesive crown mechanically locking the suspension to the flexible conductor in their desired alignment.
In this and like embodiments, typically, the method also includes forming a series of laterally and longitudinally distributed channels for registration with a plurality of attachment loci for the flexible conductor and the suspension, and where the suspension comprises a load beam and a flexure, there is further included forming at least one the channel in the load beam, and forming at least two channels in the flexure, e.g. in suspension flexure left and right tabs projecting beyond the load beam, and including also forming one of the two flexure channels in each of the flexure tabs, the flexible conductor being fixed to the tabs and fixed to the load beam with the adhesive, exposing the adhesive to UV curing radiation to cure the adhesive, and the products made thereby.
The invention in a further embodiment further provides the single-side method of mounting a flexible conductor comprising a plurality of conductors and a flexible plastic layer to a suspension comprising a load beam and a separate flexure fastened to the load beam, the flexure having left and right tabs extending laterally beyond the load beam, that includes forming in the load beam at least one flowable adhesive-passing channel at a locus of flexible conductor attachment to the load beam, the channel having an inlet and an outlet, forming in each flexure tab a flowable adhesive-passing channel at a locus of flexible conductor attachment to the flexure, each channel having an inlet and an outlet, engaging the flexible conductor and suspension in their desired alignment with the flexible conductor adjacent the channel outlet, forcing radiation curable, flowable adhesive into each channel inlet, through each channel and between the aligned suspension and flexible conductor in a manner forming a crown of the adhesive over and around each the channel inlet, curing the adhesive by radiation exposure at each channel inlet, the adhesive curing in bonding relation with the flexible conductor and the suspension, the adhesive crowns mechanically locking the suspension to the flexible conductor in their the desired alignment at each locus of attachment.
In a product embodiment, the invention provides a fixed assembly of a suspension and flexible conductor, the suspension defining at a locus of attachment between the suspension and the flexible conductor a through-channel having an inlet and an outlet, a crowned mass of hardened adhesive in the channel, the adhesive extending from the channel outlet onto the flexible conductor in bonding relation and from the channel inlet to form the crown in mechanical locking relation of the suspension to the flexible conductor.
In this and like embodiments, the invention provides a suspension having a series of laterally and longitudinally distributed through-channels for registration with a plurality of attachment loci for the flexible conductor and the suspension, and where the suspension comprises a load beam and a flexure, there is at least one through-channel in the load beam, and the flexure has at least at least two through- channels, the suspension flexure has left and right tabs projecting beyond the load beam, one of the two flexure through-channels being located in each of the flexure tabs, the flexible conductor being fixed to the tabs and fixed to the load beam with the adhesive, and the adhesive is UV radiation cured.